Duplex printing-telegraph system.



C. G. ASHLEY.

DUPLEX PRINTING TELEGRAPH SYSTEM.

APPLICATION FILED MAY 7, I9I7.

Patented Apr. 22, I919.

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UNITED STATES PATE CHARLES G. ASHLEY, OF TORONTO, ONTARIO, CANADA, ASSIGNOR TO GENERAL ENGINEERING AND CONSTRUCTION COMPANY, LIMITED, OF TORONTO, ON- TARIO, CANADA, A CORPORATION OF ONTARIO, CANADA.

DUPLEX PRINTING-TELEGRAPH SYSTEM.

Specification of Letters Patent.

Patented 14191222, 1919.

To all whom it may concern:

Be it known that I, CHARLES G. ASHLEY, a citizen of the United States of America, and a resident of the city of Toronto, county of York, and Province of Ontario, Canada, have invented a new and useful Improvement in Duplex Printing-Telegraph Systems, of which the following is a specification. y t

My invention relates to rapid printing telegraph systems, of the class in which the characters necessary for the transmission of intelligence are built up of impressions, in

proper relation and sequence, from a com-' paratively small number of typesrepresenting the various component parts of the letters or numerals to be formed, and pertains specifically to duplex arrangements of such systems. a V

The object of my invention in general comprises an improvement on my Patent No.

. 1,193,217, August 1st, 1916, specifically my object is to provide a duplex printing telegraph system which shall embody ;all the I linked to the line.

. armature 3 and slip rings 4 and 5 carried on a shaft 8. The shaft 8 carries a pinion 11 which meshes with spur gear 10 carried on a shaft 9, which carriesalso rigidly attached thereto a sprocket wheel 12. The perforated transmitting tape, used with systems of this tylpe, is engaged by the teeth of the sprocket W eeland the tape is thus drawnbetween the platen 13 and the brushes 14 and 15 in step with the alternations of the alternating current generated in the armature 3. Such transmittlng mechanism is illustrated and described in my Patent No. 1,095,541, May 5th, 1914, and is believed to be sufficiently old in the art to require no detailed description. It is usual, however, with such transmitting mechanism to connect one slip ring to earth, the other ring to the platen, and the brushes With the line conductors, and thusthe connection of the line with earth is rapidly interrupted by the passage under the brushes of a perforated tape. In contradistinction to such systems I connect brush 7 to platen 13, brush 6 through conductor 16 with the corresponding terminals of the primaries of two transformers l9 and 20, the remaining terminals of these transformers are connected to brushes 14 and 15 respectively. One terminal of the secondary of transformer 19 is connected to earth while the remaining terminal is connectedthrough conductor 21 with the conductor joining the coils 29 and 30 of the retardation coil 23, the remaining terminal of coil 29 is connected to line conductor25 while the remaining terminal of coil 30 is connected to earth through an artificial line 27. Similarly one terminal of the. secondary of transformer 20 is connected to earth and the remaining terminal is connect ed to line conductor 26 and to the artificial line'28 through the balanced coils 31 and 82 of the retardation coil 24. Thus the extremities of. the line conductors 25 and 26 are always permanently and uninterruptedly connected to earth because the perforated transmitting tape in passing between the platen 13 and thebrushes 14 and15 merely opens and closes the primary or local circuit of the (transformers 19 and 20 to send through the action of the transformers 19 and 20 the selected impulses over the line conductors 25 and 26. 1 a

In order to scavenge the line conductors from static effects and to prevent tailings, brush 7 of the generator is connected through resistances 17 and 18 with the transmitter brushes 14 and 15, that through the action of the transformers 19 and 20 an uninterrupted alternating current of low intensity in phase with-the transmitting impulses maybe placed on the line at all times. The ace. tion of the transmitting tape therefore is to the scavenging or curb current tobe aug mented through short circuiting the curb resistances 17 and 18. p

Th'e'transmitting mechanism as \Vlll now be seen comprises merely ameansdor placing 1' selectively upon the line conductors selected Hal-f w ves-er alternately current =01 pie; determihed' polarity and in predetermined sequence-.

The receiving apparatus Y com-prises four polarized relays 'et3,63',- 73* an'd-88; The windings 4:7; 48 and -67, 68* of onefpalr "of these polarized relays are con'n'ected in series and, to the" terminalspf acoil 33 Wound on;

tlfe cDie of the retardation coil" 235 Similarly'thejwindingsof pol-ariz'edrelays 73 and 83 "are connected lli-series and to a coil carried} on i the core e1 retardation 0011 24.-

Asindieeted *on the extremities of the permapolarized e6 netthey my be selectively of current from theline Wires through the coils'"a"s""29 and 30, a11'cl3'1ja'nd'32 1n se'r'i'es'; Currenti im ulses from the home or 100111 transmittingdevice'ilivid'e equally, owing to; the artificial li'nes 27" and 28, and 'pass throng-11*- the" coils 2'9 and 30, and 31" and on the" retardation coils in opposite -direc tions, the" action being the same in a diff e're'iitialftluplexg' with "the 'resultthat no current is; indiflcedfifthe coils33 and "34 and the poldrigedirelays cpiiiiectd to the'secoils" are therefore notifailected or "operated by" impulses'fronrthe lioinetiansrnitter;

Tiie-ar eture's" 451, 66; and 88 ofthe polarized "Ter y's is, ts, 73' and 83 I memeti've'ly are" all conne'oted to one terminal of condenser-$ 42, 62, 72fandf82 'respfectively, the remainii'igfterminals ofthese' condensers are con ected; through a common retnrn' conductor 35 with one" terminal; say the negative',"of a source ofclirect current; The ai ihature's of the "polarized relays are all biased to rest against ee -res ending relay contacts "45, 6 5, 75' and 85, and these correspon'diiig relay" contacts are comi'ected throughballastIresistances41f61, 71*:i'n'd' 81 respectively with the'comnion return conductor; The open contacts 19, 69, 9 and 89'f'of tli'e coils are "connected by conductors 90, 92 and 93 respectively With one term'inal of the" operating, megs-ere of the" -receiver printer 5o, 60; "and so respectiyely, the remainin-gltermin'alsof these receiver printr"coilsare "all joined to common return conductor 36 which is connected to' the K positive terminal of the 7 direct current source. The recelver printer 1s essentially the same as that described \1I1 my Patent 193,217, August 1st, 1916, and comprises four piintingfl nembers as "52, 5 3', Biand 55, 'each'bearing'atype as 52 53 ,"54c "'and 55 Whichis adapted to print an impression of a letter or numeral component. These type bearingmembers are pivoted in a support 59 by means of a pin 51. A strip ofimpr'es'sion paper or typewriter ribbon 57 is maintained above a strip of receiving tape 56, which by suitable mechanism, is drawn between the type members and I an anvil 58 and is 1 maintained thereby 'adjacent to the 'type "faces in ore-mt receiveimpressions therefrom; The building up of the letters -or numerals in this;

type'oireceiveriprinterisin *all respects similarf' to that described in In-y 'patent herein operation of "the local receiver'- apparatus as follows: I

Incoming current impulses on line 25' traverse coil fol?- retardation-e111 23 i then the current impulse divides andi'part of thecurrent is *l'd through conduetors'l through the" secjoilclariy of- 'transfornier 19 to earth-"While the other pornon ofithejcnrrentds" led through coil and artificial line 27 to earth.

A's the incoming. current impulse *traversescoils 29' and 3'0; of retardationfoil '23 in ser es, and 1n thesamedirection, current is induced in @011 23: This'xinduced wimpulse traverses the windings ofthe'relays is and;

63 and dependent upon the?pnlarityof this" indiicediinpulse' the"armatiire of either relay 43 01 63 is movedto break'con-ta'ct ithits contactyof rest andmake contactfwith its normally open"coiitact, fand A'tlfe" armature of the remaining" relay of thepair isheld more tightlyinitsinormal position. We Wines sumefthat' the polarit er the impulse in question is such as to operate" armature 44 to 1-ee1 contactwith Con act 45 and mske contact With contact 49 thus circuit'isnorn'i'ally formed from the negative terminal of the direct current source "through conductor 35, oondenser 4-2, a'rmati1're"44,- contact 49, conductor 90, receiver? printer" coil 5'0 and through conductor 36' ith the posi-' tive sideo'f'the directeurrentsource. The

condenser 42 is thus momentarily connected, in series With thereceiver printer coil 50, to the source of direct current and therefore a rush of current takes place through the coil to charge the condenser 42 to the potential of the direct current source which results in operating the printing member 52 to record its type face 52 The armature 44 after, as has been stated, momentarily making contact With contact 49 falls back to its normal position of rest in contact with contact 45, and the condenser 42 is therefore discharged through the resistance 41 Similarly a current impulse of the opposite polarity over line 25 induces a current impulse in coil 33 Which results in operating relay 63 to print member 53. Likewise impulses of predetermined polarity operate relays 73 and 83 to cause their associated receiving printing magnets 70 and 80 respectively to operate their associated printing members 54 and 55 to record type faces 54 and 55 Thus through the proper selection of impulses, letters and numerals may be recorded upon the receiving tape 56 as explained in my patent hereinbefore referred to.

It is apparent from the foregoing that my improved duplex printing telegraph system is extremely simple, that as the extremities of the duplexed lines are through the transmitting transformers and artificial lines al- Ways permanently grounded that a balance once obtained is not interrupted or destroyed by the passage of the perforated tape through the transmitting mechanism. Further, as the receiving devices are not physically connected to the line but are inductively linked thereto it is obvious that disturbances caused by earth currents are reduced to a minimum.

While I have illustrated and described but one embodiment of my device it is to be clearly understood that I am not limited thereto but may make numerous changes in the details'thereof Without departing from the spirit or narrowing the scope of my invention.

Having thus described my invention What I claim as new and desire to secure by United .States Letters Patent is as follows:

1. In a printing telegraph duplex, a pair of transformers, line conductors connected to earth through the secondaries of said transformers, transmitting apparatus connected to the primary of said transformers, a pair of retardation coils, balancing means for said line conductors, and receiving apparatus inductively linked to said line conductors through said retardation coils.

2. In a printing telegraph duplex, a pair of transformers, balanced line conductors connected to earth through the secondaries of said transformers, transmitting appalratus connected to the primary of said transformers, a pair of retardation coils connected to said line conductors, a plurality of polarized relays inductively linked to said line conductors through said retardation coils, and a receiver printer operated by said polarized relays.

3. In a printing telegraph duplex, a pair of balanced line conductors, a plurality of transformers connected to said line conductors, transmitting apparatus connected to said line conductors through certain of said transformers, a plurality of polarized relays inductively linked to said line conductors through certain other of said transformers, and a receiver printer operated by said relays.

4. In a printing telegraph duplex, a transformer, a line conductor connected to earth through the secondary ofsaid transformer, transmitting apparatus connected to the primary of said transformer, a retardation coil, balancing means for said line conductor and receiving apparatus inductively linked to said line conductor through said retardation coil.

Signed by me at Toronto, county of York and Province of Ontario, this 2nd day of May, 1917.

CHARLES G. ASHLEY. Witnesses:

A. B. CAMPBELL, L. Nnwsonm.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

